399th Avenue over North Br Twelve Mile Ck
Poor Condition54 years old71 vehicles/day
Location
| State | South Dakota |
| County | Davison |
| Location | 12 W & 0.4 N Ethan |
| Carries | 399th Avenue |
| Crosses | North Br Twelve Mile Ck |
| Coordinates | 43.54656, -98.22400 |
Condition Ratings
| Overall Condition | Poor |
| Deck | 6 (Satisfactory) |
| Superstructure | 5 (Fair) |
| Substructure | 4 (Poor) |
| Channel/Waterway | 7 (Good) |
| Scour Critical | Unknown |
Physical Characteristics
| Material | Concrete |
| Design | Channel Beam |
| Total Length | 27.6 ft (8.4 m) |
| Max Span | 26.9 ft (8.2 m) |
| Deck Width | 31.8 ft (9.7 m) |
| Deck Area | 81.5 sq m |
| Main Spans | 1 |
| Year Built | 1972 |
Traffic
| Avg Daily Traffic | 71 (2022) |
| Truck Traffic | 2% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | 724 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 000000018050206 |